In 1951, Charpentier in France synthesised Chlorpromazine with the aim of creating a centrally acting antihistamine to assist with general anaesthesia. Later, studies conducted by Delay and Deniker provided evidence for its effectiveness in treating schizophrenia.

A Historical Note on the Development of Zimelidine, the First Selective Serotonin Reuptake Inhibitor

In 1960s, evidence began to emerge suggesting a significant role of serotonin in depression. This led to the development of zimelidine, the first selective serotonin reuptake inhibitor (SSRI). Zimelidine was derived from pheniramine and was marketed in Europe in 1982. However, it was removed from the market in 1983 due to severe side effects such as hypersensitivity reactions and Guillain-Barre syndrome.

Despite its short-lived availability, zimelidine paved the way for the development of other SSRIs such as fluoxetine, which was approved by the FDA in 1987 and launched in the US market in 1988 under the trade name Prozac. The development of SSRIs revolutionized the treatment of depression and other mood disorders, providing a safer and more effective alternative to earlier antidepressants such as the tricyclics and MAO inhibitors.

The four moral principles are a useful tool in clinical practice. For instance, if a patient arrives in critical condition after a car accident and is unable to provide informed consent, the principle of beneficence requires healthcare professionals to prioritize treatment for the patient. The principle of justice may also be considered if there are many patients in need of care of if the treatment is expensive of scarce, potentially depriving others of medical attention. Non-maleficence is relevant if the treatment is likely to cause more harm than good. Respect for autonomy is important if the patient has previously expressed a desire to decline treatment in such circumstances.

The Cerebellum: Anatomy and Function

The cerebellum is a part of the brain that consists of two hemispheres and a median vermis. It is separated from the cerebral hemispheres by the tentorium cerebelli and connected to the brain stem by the cerebellar peduncles. Anatomically, it is divided into three lobes: the flocculonodular lobe, anterior lobe, and posterior lobe. Functionally, it is divided into three regions: the vestibulocerebellum, spinocerebellum, and cerebrocerebellum.

The vestibulocerebellum, located in the flocculonodular lobe, is responsible for balance and spatial orientation. The spinocerebellum, located in the medial section of the anterior and posterior lobes, is involved in fine-tuned body movements. The cerebrocerebellum, located in the lateral section of the anterior and posterior lobes, is involved in planning movement and the conscious assessment of movement.

Overall, the cerebellum plays a crucial role in motor coordination and control. Its different regions and lobes work together to ensure smooth and precise movements of the body.

Puberty

Puberty is a natural process that occurs in both boys and girls. The age range for the onset of puberty is between 8-14 years for females and 9-14 years for males, with the mean age of onset being 11 years for girls and 12 years for boys. The duration of puberty is typically 3-4 years. The onset of puberty is marked by the appearance of secondary sex characteristics, such as breast development in females and testicular enlargement in males. These characteristics evolve over time and are rated into 5 stages according to Tanner’s criteria. The sequence of events differs between boys and girls, with the onset of breast development (thelarche) generally preceding the onset of the first period (menarche) by around 2 years in girls. The pubertal growth spurt occurs during stages 3 to 4 in most boys and during stages 2 and 3 in girls. Precocious puberty, which occurs earlier than usual, is more common in girls than in boys. The age of onset of puberty in girls has been decreasing over time, with environmental factors such as nutrition potentially playing a role in this trend.

Mechanisms of Action of Different Drugs

Understanding the mechanisms of action of different drugs is crucial for medical professionals. It is a common topic in exams and can earn easy marks if studied well. This article provides a list of drugs and their mechanisms of action in different categories such as antidepressants, anti dementia drugs, mood stabilizers, anxiolytic/hypnotic drugs, antipsychotics, drugs of abuse, and other drugs. For example, mirtazapine is a noradrenaline and serotonin specific antidepressant that works as a 5HT2 antagonist, 5HT3 antagonist, H1 antagonist, alpha 1 and alpha 2 antagonist, and moderate muscarinic antagonist. Similarly, donepezil is a reversible acetylcholinesterase inhibitor used as an anti dementia drug, while valproate is a GABA agonist and NMDA antagonist used as a mood stabilizer. The article also explains the mechanisms of action of drugs such as ketamine, phencyclidine, buprenorphine, naloxone, atomoxetine, varenicline, disulfiram, acamprosate, and sildenafil.

ICD-10’s Anankastic personality disorder is the same as DSM V obsessive-compulsive personality disorder, while inadequate and passive aggressive personality disorders are not recognized in either classification system. Additionally, DSM V includes narcissistic personality disorder as a distinct category of personality disorder.

Delayed Seizures in Metrazol-Induced Convulsions

During the early development of electroconvulsive therapy (ECT), chemical convulsions using Metrazol were commonly used. However, this method was associated with a high risk of fractures due to the violent seizures induced. To address this issue, various forms of muscle relaxation were introduced, leading to the replacement of chemical convulsions with ECT.

Despite the risks associated with Metrazol-induced convulsions, they were noted to be effective for severe depression. However, delayed seizures were a common occurrence with this method.

Aripiprazole and olanzapine are preferred over haloperidol due to its high impact on the QTc interval. Risperidone can also be considered as a viable option in cases where the QTc interval is elevated.

Amantadine and QTc Prolongation

Amantadine is a medication used to treat Parkinson’s disease and influenza. It has been associated with QTc prolongation, which can increase the risk of Torsades de points. Therefore, caution should be exercised when prescribing amantadine to patients with risk factors for QT prolongation. If a patient is already taking amantadine and develops a prolonged QTc interval, the medication should be discontinued and an alternative treatment considered. It is important to monitor the QTc interval in patients taking amantadine, especially those with risk factors for QT prolongation.

Serotonin: Synthesis and Breakdown

Serotonin, also known as 5-Hydroxytryptamine (5-HT), is synthesized in the central nervous system (CNS) in the raphe nuclei located in the brainstem, as well as in the gastrointestinal (GI) tract in enterochromaffin cells. The amino acid L-tryptophan, obtained from the diet, is used to synthesize serotonin. L-tryptophan can cross the blood-brain barrier, but serotonin cannot.

The transformation of L-tryptophan into serotonin involves two steps. First, hydroxylation to 5-hydroxytryptophan is catalyzed by tryptophan hydroxylase. Second, decarboxylation of 5-hydroxytryptophan to serotonin (5-hydroxytryptamine) is catalyzed by L-aromatic amino acid decarboxylase.

Serotonin is taken up from the synapse by a monoamine transporter (SERT). Substances that block this transporter include MDMA, amphetamine, cocaine, TCAs, and SSRIs. Serotonin is broken down by monoamine oxidase (MAO) and then by aldehyde dehydrogenase to 5-Hydroxyindoleacetic acid (5-HIAA).

History of Psychiatric Terms

In the exams, it is important to be familiar with the individuals associated with certain psychiatric terms. For example, Kraepelin is associated with dementia praecox and manic depression, while Bleuler is associated with schizophrenia. Other terms and their associated individuals include Hebephrenia (Hecker), Catatonia (Kahlbaum), Schizoaffective (Kasanin), Neurasthenia (Beard), Unipolar and bipolar (Kleist), Hypnosis (Braid), Group dynamics (Lewin), Group psychotherapy (Moreno), Psychopathic inferiority (Koch), Psychiatry (Reil), and Institutional Neurosis (Barton).

It should be noted that there is some debate over the origins of certain terms. While Kraepelin is often credited with coining the term dementia praecox, some sources suggest that it was first used in its Latin form by Arnold Pick in 1891. The original term demence precoce was first used by Morel in 1852. Despite this, the College appears to favor the Kraepelin attribution.

A Historical Note on the Development of Zimelidine, the First Selective Serotonin Reuptake Inhibitor

In 1960s, evidence began to emerge suggesting a significant role of serotonin in depression. This led to the development of zimelidine, the first selective serotonin reuptake inhibitor (SSRI). Zimelidine was derived from pheniramine and was marketed in Europe in 1982. However, it was removed from the market in 1983 due to severe side effects such as hypersensitivity reactions and Guillain-Barre syndrome.

Despite its short-lived availability, zimelidine paved the way for the development of other SSRIs such as fluoxetine, which was approved by the FDA in 1987 and launched in the US market in 1988 under the trade name Prozac. The development of SSRIs revolutionized the treatment of depression and other mood disorders, providing a safer and more effective alternative to earlier antidepressants such as the tricyclics and MAO inhibitors.

In a survey conducted by Nock et al.1, which involved interviewing more than 80,000 individuals across 17 countries regarding suicidal behaviors, it was discovered that 60% of individuals who transitioned from suicidal ideation to planning and attempting suicide did so within the first year of experiencing ideation.

Inhibited Mania

Inhibited mania is one of the six mixed affective states identified by Kraepelin. It is characterized by symptoms of both mania and depression, but with a predominance of depressive features. Patients with inhibited mania may experience feelings of sadness, guilt, and worthlessness, as well as decreased energy and motivation. At the same time, they may also exhibit symptoms of mania, such as increased activity, impulsivity, and irritability.

Inhibited mania is considered an autonomous mixed episode, meaning that the patient consistently experiences symptoms of both mania and depression. This type of mixed state is associated with a poorer prognosis compared to those occurring between transitions from one mood state to another.

Treatment for inhibited mania typically involves a combination of mood stabilizers, antidepressants, and psychotherapy. It is important for clinicians to carefully monitor patients with inhibited mania, as they may be at increased risk for suicide and other adverse outcomes.

Narcolepsy is identified by a set of four symptoms, including excessive sleepiness, hypnagogic hallucinations, sleep paralysis, and cataplexy. Cataplexy is a brief and sudden weakening of muscle control, typically brought on by emotional triggers, and is frequently observed in individuals with narcolepsy.

Sleep Disorders

The International Classification of Sleep Disorders (ISCD) categorizes sleep disorders into several main categories and subclasses. Dyssomnias are intrinsic sleep disorders that include narcolepsy, psychopsychologic insomnia, idiopathic hypersomnia, restless leg syndrome, periodic limb movement disorder, and obstructive sleep apnea. Extrinsic sleep disorders include inadequate sleep hygiene and alcohol-dependent sleep disorder. Circadian rhythm disorders consist of jet lag syndrome, shift work sleep disorder, irregular sleep-wake pattern, delayed sleep phase syndrome, and advanced sleep phase disorder. Parasomnias include arousal disorders such as sleepwalking and sleep terrors, sleep-wake transition disorders such as rhythmic movement disorder, sleep talking, and nocturnal leg cramps, and parasomnias associated with REM sleep such as nightmares and sleep paralysis. Sleep disorders associated with medical/psychiatric disorders and proposed sleep disorders are also included in the classification.

Narcolepsy is a disorder of unknown cause that is characterized by excessive sleepiness, cataplexy, and other REM sleep phenomena such as sleep paralysis and hypnagogic hallucinations. Periodic limb movement disorder is characterized by periodic episodes of repetitive and highly stereotyped limb movements that occur during sleep. Restless legs syndrome is a disorder characterized by disagreeable leg sensations that usually occur prior to sleep onset and that cause an almost irresistible urge to move the legs. Jet lag syndrome consists of varying degrees of difficulties in initiating or maintaining sleep, excessive sleepiness, decrements in subjective daytime alertness and performance, and somatic symptoms following rapid travel across multiple time zones. Shift work sleep disorder consists of symptoms of insomnia of excessive sleepiness that occur as transient phenomena in relation to work schedules. Non 24 hour sleep wake syndrome consists of a chronic steady pattern comprising one to two hour daily delays in sleep onset and wake times in an individual living in society. Sleepwalking consists of a series of complex behaviors that are initiated during slow-wave sleep and result in walking during sleep. Sleep terrors are characterized by a sudden arousal from slow wave sleep with a piercing scream of cry, accompanied by autonomic and behavioral manifestations of intense fear. Rhythmic movement disorder comprises a group of stereotyped, repetitive movements involving large muscles, usually of the head and neck. Sleep starts are sudden, brief contractions of the legs, sometimes also involving the arms and head, that occur at sleep onset. Nocturnal leg cramps are painful sensations of muscular tightness of tension, usually in the calf but occasionally in the foot, that occur during the sleep episode. Nightmares are frightening dreams that usually awaken the sleeper from REM sleep. Sleep paralysis is a common condition characterized by transient paralysis of skeletal muscles which occurs when awakening from sleep of less often while falling asleep.

Non-dominant parietal lobe dysfunction is indicated by the presence of anosognosia.

Parietal Lobe Dysfunction: Types and Symptoms

The parietal lobe is a part of the brain that plays a crucial role in processing sensory information and integrating it with other cognitive functions. Dysfunction in this area can lead to various symptoms, depending on the location and extent of the damage.

Dominant parietal lobe dysfunction, often caused by a stroke, can result in Gerstmann’s syndrome, which includes finger agnosia, dyscalculia, dysgraphia, and right-left disorientation. Non-dominant parietal lobe dysfunction, on the other hand, can cause anosognosia, dressing apraxia, spatial neglect, and constructional apraxia.

Bilateral damage to the parieto-occipital lobes, a rare condition, can lead to Balint’s syndrome, which is characterized by oculomotor apraxia, optic ataxia, and simultanagnosia. These symptoms can affect a person’s ability to shift gaze, interact with objects, and perceive multiple objects at once.

In summary, parietal lobe dysfunction can manifest in various ways, and understanding the specific symptoms can help diagnose and treat the underlying condition.

Verbigeration is a type of abnormality where there is a loosening of association, which can occur in severe expressive aphasia of schizophrenia. Knight’s move thinking is another example of loosening of associations, where there is a transition from one topic to another with no logical relationship between them. Neologisms are words of phrases invented by the patient to describe a morbid experience. Overinclusion is when the boundaries of concepts are widened, grouping things together that are not normally connected. Vorbeireden, of talking past the point, is when the patient seems to be about to reach the end point of a topic but never actually does. For more information, the Shorter Oxford Textbook of Psychiatry is a recommended resource.

Spider Nevus: Causes and Symptoms

A spider nevus is a common type of angioma that appears on the skin’s surface. It is usually considered a normal finding when one of two are present. However, if there is a rapid development of numerous prominent spider nevi, it may indicate an underlying liver problem. The most common cause of this condition is alcohol consumption. Pregnant women and those who use oral contraceptives are also prone to developing spider nevi due to the dilation of existing vessels on the skin surface. If you notice any unusual changes in the appearance of spider nevi, it is important to consult a healthcare professional for proper diagnosis and treatment.

Extrapyramidal side-effects (EPSE’s) are a group of side effects that affect voluntary motor control, commonly seen in patients taking antipsychotic drugs. EPSE’s include dystonias, parkinsonism, akathisia, and tardive dyskinesia. They can be frightening and uncomfortable, leading to problems with non-compliance and can even be life-threatening in the case of laryngeal dystonia. EPSE’s are thought to be due to antagonism of dopaminergic D2 receptors in the basal ganglia. Symptoms generally occur within the first few days of treatment, with dystonias appearing quickly, within a few hours of administration of the first dose. Newer antipsychotics tend to produce less EPSE’s, with clozapine carrying the lowest risk and haloperidol carrying the highest risk. Akathisia is the most resistant EPSE to treat. EPSE’s can also occur when antipsychotics are discontinued (withdrawal dystonia).

René Spitz coined the term anaclitic depression to describe the negative impact on children who are separated from their primary caregiver, such as during a hospital stay. In extreme cases, this can lead to hospitalism. Although this type of depression can hinder a child’s development, recovery is likely if the separation from the mother does not exceed three months. Ainsworth is known for her work on the strange situation procedure, while Bowlby focused on attachment and maternal deprivation. Main is associated with the adult attachment interview, and Rutter distinguished between privation and deprivation, with the former referring to a failure to form attachments.

Antidepressants and Diabetes

Depression is a prevalent condition among patients with diabetes. It is crucial to select the appropriate antidepressant as some may have negative effects on weight and glucose levels. The first-line treatment for depression in diabetic patients is selective serotonin reuptake inhibitors (SSRIs), with fluoxetine having the most supporting data. Serotonin-norepinephrine reuptake inhibitors (SNRIs) are also likely to be safe, but there is less evidence to support their use. Tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) should be avoided. These recommendations are based on the Maudsley Guidelines 10th Edition.

Alternative splicing is a crucial process in post-transcriptional processing that has significant implications. It allows a single gene to produce multiple mRNAs that encode different polypeptides by modifying the splicing pattern. However, mutations in the gene sequence can lead to either a lack of splicing of excessive splicing, resulting in diseases.

Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

QTc Prolongation: Risks and Identification

The QT interval is a measure of the time it takes for the ventricles to repolarize and is calculated from the beginning of the QRS complex to the end of the T wave. However, the QT interval varies with the heart rate, making it difficult to use a single number as a cut-off for a prolonged QT. Instead, a corrected QT interval (QTc) is calculated for each heart rate using various formulas. A QTc over the 99th percentile is considered abnormally prolonged, with approximate values of 470 ms for males and 480 ms for females.

Prolonged QT intervals can lead to torsade de pointes (TdP), a polymorphic ventricular tachycardia that can be fatal if it degenerates into ventricular fibrillation. TdP is characterized by a twisting of the QRS complexes around an isoelectric line and is often asymptomatic but can also be associated with syncope and death. An accurate diagnosis requires an ECG to be recorded during the event. It is important to note that an increase in the QT interval due to a new conduction block should not be considered indicative of acquired LQTS and risk for TdP.

Transference is the unconscious process of shifting emotions and desires from one person to another, often from a parent of sibling to the therapist. While positive transference can strengthen a patient’s weak ego during psychoanalysis, it is not enough on its own. Resistance, a defense mechanism that thwarts the therapist’s attempts to access unconscious processes, can hinder progress. Freud initially believed transference only occurred in therapy, but later expanded his view to include its presence in all relationships. He also believed that interpreting transference was crucial to the success of psychoanalysis, as the transferential relationship between therapist and patient was the curative factor.

Due to its extended half-life, Donepezil is administered once daily and functions as an acetylcholinesterase inhibitor.

Pharmacological management of dementia involves the use of acetylcholinesterase inhibitors (AChE inhibitors) and memantine. AChE inhibitors prevent the breakdown of acetylcholine, which is deficient in Alzheimer’s due to the loss of cholinergic neurons. Donepezil, galantamine, and rivastigmine are commonly used AChE inhibitors in the management of Alzheimer’s. However, gastrointestinal side effects such as nausea and vomiting are common with these drugs.

Memantine, on the other hand, is an NMDA receptor antagonist that blocks the effects of pathologically elevated levels of glutamate that may lead to neuronal dysfunction. It has a half-life of 60-100 hours and is primarily renally eliminated. Common adverse effects of memantine include somnolence, dizziness, hypertension, dyspnea, constipation, headache, and elevated liver function tests.

Overall, pharmacological management of dementia aims to improve cognitive function and slow down the progression of the disease. However, it is important to note that these drugs do not cure dementia and may only provide temporary relief of symptoms.

Susto is an anxiety disorder prevalent in South and Central America that is linked to the loss of soul. It typically occurs after experiencing a traumatic emotional of physical event.

Amok is a dissociative state that is more commonly observed in Malaysia. It is characterized by symptoms such as neurasthenia, depersonalization, rage, automatism, and violent acts.

Koro is a belief that the penis is shrinking and will retract into the abdomen, leading to death.

Latah is a condition similar to Tourette’s syndrome, where an exaggerated startle response results in abnormal behaviors.

Wendigo is a depressive disorder that involves the delusion of becoming cannibalistic. It is primarily observed in Native American communities.

The Use of Star Charts in Behavioral Management

Star charts have proven to be effective in managing enuresis, encopresis, and acute phase despondency. In cases of encopresis, the star chart reward system has been successful in about 20 to 30% of cases. The use of a wall chart to graphically depict the time spent off the ventilator each day has also been effective in patients with severe ventilator impairments.

The reward system in the form of a star chart is a type of positive reinforcement, where behavior is strengthened by the presentation of something pleasant. This is a form of operant conditioning, where the animal is active and learns through action. In contrast, classical conditioning involves passive of restrained animals and the use of conditioned and unconditioned stimuli.

Social learning theories rely on role modeling, identification, and human interactions. While social learning combines classical and operant conditioning, observation of models may be a major factor in the learning process. Higher order conditioning is another form of classical conditioning, where a conditioned stimulus is paired with another stimulus to produce a further conditioned response.

Cytochrome P450 is an important enzyme system involved in drug metabolism. Certain substances can either increase or decrease the activity of this system. Smoking, alcohol, barbiturates, carbamazepine, Phenytoin, and St John’s Wort are known to induce the activity of cytochrome P450. On the other hand, chlorpromazine, selective serotonin reuptake inhibitors (SSRIs), and grapefruit juice are known to inhibit the activity of cytochrome P450.

The Cytochrome P450 system is a group of enzymes that metabolize drugs by altering their functional groups. The system is located in the liver and small intestine and is involved in drug interactions through enzyme induction of inhibition. Notable inducers include smoking, alcohol, and St John’s Wort, while notable inhibitors include grapefruit juice and some SSRIs. CYP2D6 is important due to genetic polymorphism, and CYP3A4 is the most abundant subfamily and is commonly involved in interactions. Grapefruit juice inhibits both CYP1A2 and CYP3A4, while tobacco smoking induces CYP1A2. The table summarizes the main substrates, inhibitors, and inducers for each CYP enzyme.

Antidepressants (Licensed Indications)

The following table outlines the specific licensed indications for antidepressants in adults, as per the Maudsley Guidelines and the British National Formulary. It is important to note that all antidepressants are indicated for depression.

– Nocturnal enuresis in children: Amitriptyline, Imipramine, Nortriptyline
– Phobic and obsessional states: Clomipramine
– Adjunctive treatment of cataplexy associated with narcolepsy: Clomipramine
– Panic disorder and agoraphobia: Citalopram, Escitalopram, Sertraline, Paroxetine, Venlafaxine
– Social anxiety/phobia: Escitalopram, Paroxetine, Sertraline, Moclobemide, Venlafaxine
– Generalised anxiety disorder: Escitalopram, Paroxetine, Duloxetine, Venlafaxine
– OCD: Escitalopram, Fluoxetine, Fluvoxamine, Paroxetine, Sertraline, Clomipramine
– Bulimia nervosa: Fluoxetine
– PTSD: Paroxetine, Sertraline

Understanding Turner Syndrome

Turner syndrome is a genetic disorder that affects only females. It occurs when one of the two X chromosomes is missing of partially missing. This happens randomly and does not increase the risk of the condition in future siblings. Although X-inactivation occurs in females, having only one X chromosome can cause issues as not all genes are inactivated in the inactivated X chromosome.

The features of Turner syndrome include short stature, a webbed neck, a broad chest with widely spaced nipples, gonadal dysfunction leading to amenorrhea and infertility, congenital heart disease, and hypothyroidism. Despite these physical characteristics, girls with Turner syndrome typically have normal intelligence, with a mean full-scale IQ of 90. However, they may struggle with nonverbal, social, and psychomotor skills. It is important to understand the symptoms and effects of Turner syndrome to provide appropriate care and support for affected individuals.

Panic disorder is a mental health condition that is characterized by sudden and intense episodes of anxiety that often occur without warning. Physical symptoms such as palpitations and dizziness are common during these episodes. Fear of collapsing of dying is a common psychological symptom associated with this disorder. Free-floating anxiety is a feature of generalized anxiety disorder, while situational anxiety is more characteristic of specific phobic anxiety. The International Classification of Diseases (ICD-10) classifies panic disorder as F41.0, also known as episodic paroxysmal anxiety.

Neurotrophins: Crucial for Neuronal Growth and Development

Neurotrophins are essential for the growth and development of neurons. However, disturbances in neurotrophic factors may contribute to some neurodevelopmental aspects of schizophrenia and major depression.

Studies have shown that patients with schizophrenia have increased concentrations of Brain-derived neurotrophic factor (BDNF) in cortical areas, but decreased levels in the hippocampus compared to controls. Additionally, patients with schizophrenia have lower concentrations of neurotrophin-3 in frontal and parietal areas than controls.

These findings suggest that neurotrophins play a critical role in the pathophysiology of schizophrenia and major depression. Further research is needed to fully understand the mechanisms underlying these disturbances in neurotrophic factors.

Mechanisms of Action of Different Drugs

Understanding the mechanisms of action of different drugs is crucial for medical professionals. It is a common topic in exams and can earn easy marks if studied well. This article provides a list of drugs and their mechanisms of action in different categories such as antidepressants, anti dementia drugs, mood stabilizers, anxiolytic/hypnotic drugs, antipsychotics, drugs of abuse, and other drugs. For example, mirtazapine is a noradrenaline and serotonin specific antidepressant that works as a 5HT2 antagonist, 5HT3 antagonist, H1 antagonist, alpha 1 and alpha 2 antagonist, and moderate muscarinic antagonist. Similarly, donepezil is a reversible acetylcholinesterase inhibitor used as an anti dementia drug, while valproate is a GABA agonist and NMDA antagonist used as a mood stabilizer. The article also explains the mechanisms of action of drugs such as ketamine, phencyclidine, buprenorphine, naloxone, atomoxetine, varenicline, disulfiram, acamprosate, and sildenafil.

The correct answer is the Lazarus theory, which proposes that emotions are the result of cognitive appraisal of a situation. According to this theory, the thought I’m being burgled triggers a cognitive appraisal of the situation, which in turn leads to the emotional response of fear. This is in contrast to the Singer-Schachter theory, which suggests that emotions are the result of a combination of physiological arousal and cognitive interpretation of that arousal.

Theories of Emotion

In membership exams, four main theories of emotion are commonly discussed: James-Lange theory, Cannon-Bard theory, Singer-Schachter theory, and Lazarus theory. The key to understanding the differences between these theories is to identify where the stimulus for the emotion arises.

According to the James-Lange theory, emotions occur as a result of bodily sensations. For instance, if you see a big dog, your heart races, and you feel afraid. This theory proposes that certain external stimuli stimulate specific sensory organs, leading to a particular emotion. The sequence of events suggested by this theory is as follows: event – arousal – interpretation – emotion. In other words, the stimulus for emotion arises from physical sensations.

The Cannon-Bard theory, also known as the thalami theory, proposes that when an event occurs, one experiences an emotion at the same time as physiological changes. The stimulus for emotion arises simultaneously in the body and the mind.

The Singer-Schachter theory, also known as the two-factor theory, suggests that emotions result from both physiological changes and the context. For example, if your heart is racing, and you are about to have an exam, you label yourself as afraid. However, if your heart is racing, and you are about to kiss your partner, you label your emotional state as excited. The stimulus for emotion arises via a combination of physical sensations and the mind’s appraisal of them.

Finally, the Lazarus theory proposes that a thought is required before an emotion occurs. For instance, if you see a big dog, you think it is going to bite you, and you feel afraid. The stimulus for emotion arises from the mind.

In summary, these theories offer different perspectives on the relationship between physical sensations, cognitive processes, and emotions.

– Visual aura is not expected in temporal lobe epilepsy
– Visual aura may occur in occipital seizures
– Temporal lobe epilepsy is characterized by automatisms, altered consciousness, déjà vu, complex partial seizures, and olfactory hallucinations
– Occipital epilepsy can cause visual phenomena and headaches
– Occipital epilepsy should be differentiated from migraine

Throughout his career, Szasz contended that mental illness is merely a metaphor for difficulties in human existence, and that mental illnesses lack the objective reality of physical ailments like cancer. He opposed many aspects of the contemporary psychiatric system in developed countries.

Antipsychiatry is a movement that emerged in the 1960s and challenges the traditional medical model of mental illness. It argues that mental illnesses are not biological of medical conditions but rather social constructs that reflect deviations from social norms. The movement has been associated with several famous figures, including Thomas Szasz, R.D. Laing, Michel Foucault, and Franco Basaglia. These individuals have criticized the psychiatric profession for its use of involuntary hospitalization, medication, and other forms of coercion in the treatment of mental illness. They have also advocated for alternative approaches to mental health care, such as community-based care and psychotherapy. Despite its controversial nature, the antipsychiatry movement has had a significant impact on the field of mental health and continues to influence the way we think about and treat mental illness today.

Water intoxication can cause polyuria and dilutional hyponatremia, but it does not typically lead to renal impairment. It is important to differentiate this condition from nephrogenic diabetes insipidus, which can develop in a significant percentage of patients on long-term lithium therapy and may present with nocturia as an early sign. While elevated calcium levels may occur in some patients on lithium, hyperparathyroidism is not a common clinical symptom. Tubulointerstitial nephritis is a rare complication of lithium therapy. The syndrome of inappropriate ADH secretion is not typically associated with polyuria of renal impairment and is not commonly linked to lithium therapy.

Lithium – Pharmacology

Pharmacokinetics:
Lithium salts are rapidly absorbed following oral administration and are almost exclusively excreted by the kidneys unchanged. Blood samples for lithium should be taken 12 hours post-dose.

Ebstein’s:
Ebstein’s anomaly is a congenital malformation consisting of a prolapse of the tricuspid valve into the right ventricle. It occurs in 1:20,000 of the general population. Initial data suggested it was more common in those using lithium but this had not held to be true.

Contraindications:
Addison’s disease, Brugada syndrome, cardiac disease associated with rhythm disorders, clinically significant renal impairment, untreated of untreatable hypothyroidism, low sodium levels.

Side-effects:
Common side effects include nausea, tremor, polyuria/polydipsia, rash/dermatitis, blurred vision, dizziness, decreased appetite, drowsiness, metallic taste, and diarrhea. Side-effects are often dose-related.

Long-term use is associated with hypothyroidism, hyperthyroidism, hypercalcemia/hyperparathyroidism, irreversible nephrogenic diabetes insipidus, and reduced GFR.

Lithium-induced diabetes insipidus:
Treatment options include stopping lithium (if feasible), keeping levels within 0.4-0.8 mmol/L, once-daily dose of the drug taken at bedtime, amiloride, thiazide diuretics, indomethacin, and desmopressin.

Toxicity:
Lithium salts have a narrow therapeutic/toxic ratio. Risk factors for lithium toxicity include drugs altering renal function, decreased circulating volume, infections, fever, decreased oral intake of water, renal insufficiency, and nephrogenic diabetes insipidus. Features of lithium toxicity include GI symptoms and neuro symptoms.

Pre-prescribing:
Before prescribing lithium, renal function, cardiac function, thyroid function, FBC, and BMI should be checked. Women of childbearing age should be advised regarding contraception, and information about toxicity should be provided.

Monitoring:
Lithium blood levels should be checked weekly until stable, and then every 3-6 months once stable. Thyroid and renal function should be checked every 6 months. Patients should be issued with an information booklet, alert card, and record book.

Understanding Bioavailability in Drug Trials

Bioavailability is a crucial factor in drug trials, as it determines the percentage of a drug that reaches the systemic circulation after administration. This can be affected by factors such as absorption and metabolic clearance. For example, if a drug called X is administered orally and only 60% reaches the systemic circulation, its bioavailability is 0.6 of 60%. However, if the same drug is administered intravenously, plasma levels may reach 100%.

One way to potentially increase bioavailability is through the rectal route, which bypasses around two thirds of the first-pass metabolism. This is because the rectum’s venous drainage is two thirds systemic (middle and inferior rectal vein) and one third portal (superior rectal vein). As a result, drugs administered rectally may reach the circulatory system with less alteration and in greater concentrations. Understanding bioavailability and exploring different administration routes can help optimize drug efficacy in clinical trials.

Hyperprolactinemia is a potential side effect of antipsychotic medication, but it is rare with antidepressants. Dopamine inhibits prolactin, so dopamine antagonists, such as antipsychotics, can increase prolactin levels. The degree of prolactin elevation is dose-related, and some antipsychotics cause more significant increases than others. Hyperprolactinemia can cause symptoms such as galactorrhea, menstrual difficulties, gynecomastia, hypogonadism, and sexual dysfunction. Long-standing hyperprolactinemia in psychiatric patients can increase the risk of osteoporosis and breast cancer, although there is no conclusive evidence that antipsychotic medication increases the risk of breast malignancy and mortality. Some antipsychotics, such as clozapine and aripiprazole, have a low risk of causing hyperprolactinemia, while typical antipsychotics and risperidone have a high risk. Monitoring of prolactin levels is recommended before starting antipsychotic therapy and at three months and annually thereafter. Antidepressants rarely cause hyperprolactinemia, and routine monitoring is not recommended. Symptomatic hyperprolactinemia has been reported with most antidepressants, except for a few, such as mirtazapine, agomelatine, bupropion, and vortioxetine.

The symptoms exhibited by the patient are consistent with Koro, a culture-specific disorder observed primarily in males (and occasionally in females) in China and Thailand. For more information, please refer to Edwards JW’s article Indigenous Koro, a genital retraction syndrome of insular Southeast Asia: a critical review published in Cult Med Psychiatry in 1984.

The BMI of a person is determined by dividing their weight in kilograms by the square of their height in meters, expressed as kg/m2.

The BPRS is a tool used to assess symptoms in individuals with functional mental illness. There are also various screening tools available for personality disorders, which you should have a basic knowledge of for the exam. These include the SAPAS, which is an interview method that focuses on 8 areas and takes 2 minutes to complete. It is scored between 0 and 8 based on yes/no answers to 8 statements, and a score of 3 of more warrants further assessment. The FFMRF is a self-reported tool consisting of 30 items rated 1-5 for each item, based on symptoms rather than diagnosis. The IPDE is a semistructured clinical interview compatible with the ICD and DSM, which includes both a patient questionnaire and an interview.

In psychiatry, various questionnaires and interviews are used to assess different conditions and areas. It is important for candidates to know whether certain assessment tools are self-rated of require clinical assistance. The table provided by the college lists some of the commonly used assessment tools and indicates whether they are self-rated of clinician-rated. For example, the HAMD and MADRS are clinician-rated scales used to assess the severity of depression, while the GDS is a self-rated scale used to screen for depression in the elderly. The YMRS is a clinician-rated scale used to assess the severity of mania in patients with bipolar disorder, while the Y-BOCS is used to measure both the severity of OCD and the response to treatment. The GAF provides a single measure of global functioning, while the CGI requires the clinician to rate the severity of the patient’s illness at the time of assessment. The CAMDEX is a tool developed to assist in the early diagnosis and measurement of dementia in the elderly.

Brain Abnormalities in Dyslexia

Individuals with dyslexia often exhibit a loss of the typical left-right asymmetry at the planum temporale in the temporal lobe. However, this abnormality can also be observed in the brains of individuals without dyslexia, making it a sensitive but not specific marker for the disorder. None of the other brain regions mentioned are associated with dyslexia. The pineal gland, located in the epithalamus, secretes melatonin. The third interstitial nucleus of the anterior hypothalamus is larger in heterosexual men compared to homosexual men and heterosexual women. The medulla oblongata is located in the brainstem, and the lateral geniculate nucleus in the thalamus relays visual information from the retina to the occipital cortex.

Genetic Terms

Recombination Fraction

The recombination fraction is a measure of the distance between loci on a chromosome. If two loci are on different chromosomes, they will segregate independently. However, if they are on the same chromosome, they would always segregate together were it not for the process of crossing over. The closer two loci are on a chromosome, the less likely they are to be separated by crossing over. Blocks of alleles on a chromosome tend to be transmitted as a block through pedigree, and are known as a haplotype. The recombination fraction can vary from 0% if they are extremely close and 50% if they are on different chromosomes.

Gene Mapping

Mapping the genome is done in two ways: genetic mapping and physical mapping. Genetic mapping uses techniques such as pedigree analysis, while physical mapping is a technique used to find the order and physical distance between DNA base pairs by DNA markers. Physical maps can be divided into three general types: chromosomal of cytogenetic maps, radiation hybrid (RH) maps, and sequence maps. The different types of maps vary in their degree of resolution. Both maps are a collection of genetic markers and gene loci. While the physical map could be a more ‘accurate’ representation of the genome, genetic maps often offer insights into the nature of different regions of the chromosome.

LOD Score

The LOD score (logarithm of the odds) is a method used to ascertain if there is evidence for linkage between two genes. When genes are very near to each other on a chromosome, they are unlikely to be separated during crossing over in meiosis, and such genes are said to be linked. The relative distance between two genes can be calculated by using the offspring of an organism showing two strongly linked traits, and finding the percentage of offspring where the traits do not run together. By convention, a LOD score of >3 is considered evidence for linkage, and a LOD score of <-2 excludes linkage. Epigenetic Epigenetics involves genetic control by factors other than an individual’s DNA sequence. Epigenetic changes can switch genes on of off and determine which proteins are transcribed. Penetrance Penetrance is the probability of a gene of genetic trait being expressed. ‘Complete penetrance’ means the gene of genes for a trait are expressed in all the population who have the genes. ‘Incomplete penetrance’ means the genetic trait is expressed in only part of the population. Heritability Heritability is the proportion of phenotypic variance attributable to genetic variance. Anticipation Anticipation is a phenomenon whereby the symptoms of a genetic disorder become apparent at an earlier age as it is passed on to the next generation.

Psychogenic polydipsia is a condition where there is excessive consumption of fluids leading to polyuria, and it is commonly seen in psychiatric conditions such as schizophrenia and developmental disorders. The exact mechanism is unknown, but it is thought to be due to a defect in thirst and a dysfunction in AVP regulation. Patients with psychogenic polydipsia rarely complain of thirst but instead provide delusional explanations for their excessive drinking of state that drinking reduces their anxiety and makes them feel better. If fluid intake exceeds the capacity for excretion, then the resultant hyponatremia may produce signs of water intoxication. It is best managed by fluid restriction. Differential diagnosis should be done to rule out other causes of polyuria and polydipsia. Investigations such as fluid balance charts, urine dipstick, serum U&E and calcium, and urine and plasma osmolality should be arranged. Primary polydipsia can be subclassified into psychogenic and dipsogenic types.

Extrapyramidal side-effects (EPSE’s) are a group of side effects that affect voluntary motor control, commonly seen in patients taking antipsychotic drugs. EPSE’s include dystonias, parkinsonism, akathisia, and tardive dyskinesia. They can be frightening and uncomfortable, leading to problems with non-compliance and can even be life-threatening in the case of laryngeal dystonia. EPSE’s are thought to be due to antagonism of dopaminergic D2 receptors in the basal ganglia. Symptoms generally occur within the first few days of treatment, with dystonias appearing quickly, within a few hours of administration of the first dose. Newer antipsychotics tend to produce less EPSE’s, with clozapine carrying the lowest risk and haloperidol carrying the highest risk. Akathisia is the most resistant EPSE to treat. EPSE’s can also occur when antipsychotics are discontinued (withdrawal dystonia).

Anabolic Steroids: Uses, Misuse, and Complications

Anabolic steroids are synthetic derivatives of testosterone that have both anabolic and androgenic properties. They are commonly used by athletes to enhance performance and by individuals to improve physical appearance. However, their misuse is not uncommon, with nearly half of users of dedicated bodybuilding gyms admitting to taking anabolic agents. Misuse can lead to dependence, tolerance, and the development of psychiatric disorders such as aggression, psychosis, mania, and depression/anxiety.

There are three common regimes practised by steroid misusers: ‘cycling’, ‘stacking’ and ‘pyramiding’. Anabolic steroids can be taken orally, injected intramuscularly, and applied topically in the form of creams and gels. Other drugs are also used by athletes, such as clenbuterol, ephedrine, thyroxine, insulin, tamoxifen, human chorionic Gonadotropin, diuretics, and growth hormone.

Medical complications are common and can affect various systems, such as the musculoskeletal, cardiovascular, hepatic, reproductive (males and females), dermatological, and other systems. Complications include muscular hypertrophy, increased blood pressure, decreased high-density lipoprotein cholesterol and increased low-density lipoprotein cholesterol, cholestatic jaundice, benign and malignant liver tumours, testicular atrophy, sterility, gynaecomastia, breast tissue shrinkage, menstrual abnormalities, masculinisation, male-pattern baldness, acne, sleep apnoea, exacerbation of tic disorders, polycythaemia, altered immunity, and glucose intolerance.

Anabolic steroids are a class C controlled drug and can only be obtained legally through a medical prescription. It is important to educate individuals about the risks and complications associated with their misuse and to promote safe and legal use.

Genomic Imprinting and its Role in Psychiatric Disorders

Genomic imprinting is a phenomenon where a piece of DNA behaves differently depending on whether it is inherited from the mother of the father. This is because DNA sequences are marked of imprinted in the ovaries and testes, which affects their expression. In psychiatry, two classic examples of genomic imprinting disorders are Prader-Willi and Angelman syndrome.

Prader-Willi syndrome is caused by a deletion of chromosome 15q when inherited from the father. This disorder is characterized by hypotonia, short stature, polyphagia, obesity, small gonads, and mild mental retardation. On the other hand, Angelman syndrome, also known as Happy Puppet syndrome, is caused by a deletion of 15q when inherited from the mother. This disorder is characterized by an unusually happy demeanor, developmental delay, seizures, sleep disturbance, and jerky hand movements.

Overall, genomic imprinting plays a crucial role in the development of psychiatric disorders. Understanding the mechanisms behind genomic imprinting can help in the diagnosis and treatment of these disorders.

When using methadone and haloperidol together, it is important to closely monitor the QTc interval due to their significant effect on it. EEG and electrolyte screening are not necessary. While liver function tests may be useful to perform periodically, they are not the primary concern with this combination. It is important to be cautious of respiratory depression when using high doses of methadone in combination with other sedative medications, but respiratory function tests are unlikely to provide helpful information.